A low-pressure cylinder bypass desuperheating and equalizing device system and control method

Abstract

A low-pressure cylinder bypass temperature reduction and equalization device system, the system comprises: a low-pressure cylinder cooling bypass water spray temperature reduction part: including a pipeline where a low-pressure cylinder cooling steam bypass inlet isolation valve is located, a water spray device, and a temperature reduction water control and regulation pipeline. The system further comprises a regenerative equalization part and a low-pressure cylinder cooling steam bypass part. The system and control can solve the problem of high low-pressure cylinder exhaust temperature caused by high low-pressure cylinder cooling steam temperature after the current steam turbine low-pressure cylinder cut-off modification, save the modification of the low-pressure cylinder last stage and penultimate stage area temperature reduction water system, eliminate the risk of blade water erosion and over-temperature, and make the low-pressure cylinder cut-off modification better.

Description

TECHNICAL FIELD

[0001] The present application relates to a low-pressure cylinder bypass temperature reduction and uniform temperature device system and a control method, in particular to a low-pressure cylinder bypass temperature reduction and uniform temperature device system operation control technology after low-pressure cylinder cut cylinder modification of a thermal power generating unit steam turbine. BACKGROUND

[0002] The requirements of thermal power generating units for flexible peak regulation and power supply are increasingly high. The low-pressure cylinder cut cylinder technology reduces the low-pressure cylinder steam flow during operation, increases the heat supply capacity of the unit, and at the same time, reduces the power generation load of the unit, which is beneficial to the deep peak regulation of the unit and realizes the thermal and electrical decoupling of the unit.

[0003] Common low-pressure cylinder cut cylinder technologies include low-pressure cylinder micro-power modification and low-pressure cylinder zero-power modification. After modification, the low-pressure cylinder last stage and penultimate stage blades generally need to be sprayed, and water spray cooling is needed to control the temperature of the low-pressure cylinder last stage and penultimate stage blades. However, when the unit enters the low-pressure cylinder cut cylinder operation condition for peak regulation, the cooling flow into the low-pressure cylinder is small, and when the steam extraction pressure for heating is met, the temperature of the low-pressure cylinder cooling steam will increase, especially when the reheated steam extraction or the extraction with a rotating partition is put into operation, the pressure ratio of the intermediate-pressure cylinder decreases, causing the temperature of the cooling steam into the low-pressure cylinder to increase significantly. The increase of the inlet steam temperature will cause the temperature of the low-pressure cylinder flow passage to increase as a whole, and the exhaust steam temperature will also increase. With the increase of the cut cylinder depth and the exhaust steam temperature being greater than or equal to 70 DEG C, due to the small volume flow, the low-pressure cylinder last stage blades enter the blast operation condition, and in order to reduce the last stage exhaust steam temperature, the conventional modification method needs to be modified by water spray cooling, and the low-pressure cylinder last stage blades need to be modified by spraying.

[0004] Although the low-pressure cylinder cooling bypass directly uses the water spray cooling method, there is a risk of water entering the low-pressure cylinder due to uneven atomization or over-spraying during actual operation.

[0005] A large amount of water spray cooling water is injected into the low-pressure cylinder last stage, and there is a high risk of water erosion of the low-pressure cylinder last stage and penultimate stage blades, and the penultimate stage temperature is too high, which affects the safe operation of the steam turbine. SUMMARY

[0006] The present application provides a low-pressure cylinder bypass temperature reduction and uniform temperature device system and a control method, which can solve the problem of high temperature of the low-pressure cylinder cooling steam after the low-pressure cylinder cut cylinder modification of the steam turbine, which causes the high temperature of the low-pressure cylinder exhaust steam, and eliminates the risks of water erosion and over-temperature of the blades, and the effect is better after the low-back-pressure micro-power cut cylinder modification.

[0007] A low-pressure cylinder bypass temperature reduction and uniform temperature device system, characterized in that the system comprises:

[0008] Low-pressure cylinder cooling bypass water spray desuperheating part: including the pipeline where the low-pressure cylinder cooling steam bypass inlet isolation valve is located, a water spray device, and a desuperheating water control and adjustment pipeline;

[0009] The system can reduce the steam temperature at the low-pressure cylinder cooling steam bypass inlet through desuperheating water, avoid high low-pressure cylinder exhaust steam temperature caused by excessively high low-pressure cylinder cooling steam inlet temperature, reduce the use of low-pressure cylinder last-stage blade and penultimate blade cooling desuperheating water flow system, and effectively reduce the risk of low-pressure cylinder last-stage blade and penultimate blade water erosion.

[0010] Heat recovery type temperature equalizing part: including a heat recovery type temperature equalizer and a pipeline where a low-pressure cylinder cooling steam regulating valve is located; the system can perform filtering and temperature equalizing, heat recovery steam mixing and heating to ensure the dryness and adjustable temperature of low-pressure cylinder inlet bypass cooling steam, and adjust the low-pressure cylinder exhaust steam temperature.

[0011] Low-pressure cylinder cooling steam bypass part: including a pipeline where a low-pressure cylinder cooling steam bypass valve is located, wherein the connection relationship is that the cooling steam introduced from the intermediate-pressure cylinder is connected to the heat recovery type temperature equalizing part after passing through the low-pressure cylinder cooling bypass water spray desuperheating part, and the pipeline where the low-pressure cylinder main line cooling steam bypass valve is located in the low-pressure cylinder cooling steam bypass part is directly connected from the intermediate-pressure cylinder to the low-pressure cylinder, with a valve arranged in the pipeline. The low-pressure cylinder inlet total flow rate is matched with the unit back pressure and the low-pressure cylinder exhaust steam temperature.

[0012] The low-pressure cylinder cooling steam temperature can be adjusted according to the power generation load, heating load, unit back pressure, and low-pressure cylinder exhaust steam temperature of the unit, and the adjustment mode adopts control of the desuperheating water flow rate, the heat recovery steam flow rate entering the heat recovery type temperature equalizing device, and the low-pressure cylinder cooling steam main line flow rate.

[0013] The cooling steam introduced from the intermediate-pressure cylinder is connected with the water spray device after passing through the pipeline of the low-pressure cylinder cooling steam bypass inlet isolation valve, the desuperheated cooling steam is mixed with the steam introduced from the pipeline where the low-pressure cylinder cooling steam regulating valve is located into the heat recovery type temperature equalizer, and the mixed steam enters the low-pressure cylinder.

[0014] The mixed steam in the heat recovery type temperature equalizer enters the low-pressure cylinder through the flow rate measuring device and the low-pressure cylinder cooling steam bypass outlet isolation valve.

[0015] The temperature reducing water control adjusting pipeline comprises a cooling water source, a cooling water main pipeline, a bypass, a bypass valve, a low-pressure cylinder cooling water adjusting valve, an outlet isolation valve and an inlet isolation valve, the cooling water source is divided into the cooling water main pipeline and the bypass, the bypass is provided with the bypass valve, the cooling water main pipeline is provided with the low-pressure cylinder cooling water adjusting valve, and the inlet isolation valve and the outlet isolation valve are arranged at the front end and the rear end of the low-pressure cylinder cooling water adjusting valve respectively.

[0016] In order to facilitate monitoring and automatic control of the low-pressure cylinder cooling steam bypass and the low-pressure cylinder admission parameter during operation, pressure and temperature measuring points can be installed at necessary positions to monitor and participate in intermediate point calculation, and a flow orifice plate is installed before the cooling steam enters the low-pressure cylinder to monitor and control the bypass admission flow in real time. The pressure is designed as a two-out-of-three absolute pressure measuring point, and the temperature measuring point is in the form of a platinum resistance or a thermocouple.

[0017] The temperature of the cooling steam entering the low-pressure cylinder is adjustable, which can ensure that the last-stage and penultimate-stage blades of the low-pressure cylinder are not overheated and the dryness of the cooling steam entering the low-pressure cylinder is not affected, thereby ensuring normal operation of the low-pressure cylinder.

[0018] The regenerative temperature equalizing part comprises a regenerative temperature equalizer and a pipeline in which a low-pressure cylinder cooling steam adjusting valve is arranged; the pipeline in which the low-pressure cylinder cooling steam adjusting valve is arranged is connected with the regenerative temperature equalizer; and the cooling steam led out from the intermediate-pressure cylinder is mixed with the pipeline in which the low-pressure cylinder cooling steam adjusting valve is arranged after passing through the low-pressure cylinder cooling bypass water injection and temperature reducing part, and then is introduced into the regenerative temperature equalizer.

[0019] A control method of a low-pressure cylinder bypass temperature reducing and temperature equalizing device system, which is specifically applied to control of the low-pressure cylinder bypass temperature reducing and temperature equalizing device system: in the cylinder cutting condition, different power generation loads and heat supply loads of the unit are used to flexibly select an operation mode of the low-pressure cylinder bypass temperature reducing and temperature equalizing device system, which comprises: a flow of low-pressure cylinder main path cooling steam directly entering the low-pressure cylinder is separately adjusted; and low-pressure cylinder bypass cooling steam passes through a temperature reducing and temperature equalizing device and is used with a fixed small flow of low-pressure cylinder main path cooling steam.

[0020] Further, the operation mode that the low-pressure cylinder main path cooling steam directly enters the low-pressure cylinder comprises: in the cylinder cutting condition, the low-pressure cylinder cooling steam temperature satisfies the condition that the low-pressure cylinder exhaust temperature is not high, at this time, the low-pressure cylinder last-stage and penultimate-stage blades do not use the temperature reducing water, the low-pressure cylinder last-stage and penultimate-stage blades have no water erosion risk, and the low-pressure cylinder main path cooling steam can directly enter the low-pressure cylinder for cooling.

[0021] The operation mode of the low-pressure cylinder bypass cooling steam passing through the temperature-reducing and temperature-homogenizing device is specifically as follows: in the case that the low-pressure cylinder cooling steam temperature is relatively high, resulting in the high low-pressure cylinder exhaust steam temperature, at this time, the low-pressure cylinder bypass cooling steam flow passing through the heat recovery type homogenizer after heat recovery adjustment is used together with a certain fixed small cooling steam flow of the low-pressure cylinder main path, at this time, the low-pressure cylinder last-stage blade and the penultimate blade can not use the temperature-reducing water, and at this time, the low-pressure cylinder last-stage blade and the penultimate blade have no water erosion risk.

[0022] Each regulating valve can be automatically controlled according to the low-pressure cylinder exhaust steam temperature or the low-pressure cylinder cooling steam inlet temperature, so as to ensure that the low-pressure cylinder cooling steam inlet temperature and the low-pressure cylinder exhaust steam temperature are within a reasonable range.

DRAWINGS

[0023] Figure 1 is a block diagram of the low-pressure cylinder bypass temperature-reducing and temperature-homogenizing device system in the embodiment of the present application;

[0024] Figure 2 is a structural diagram of the heat recovery type homogenizer of the present application;

[0025] In the drawings: 1, high-pressure cylinder; 2, medium-pressure cylinder; 3, low-pressure cylinder; 4, low-pressure cylinder main path cooling steam bypass valve; 5, low-pressure cylinder cooling steam regulating valve; 6, low-pressure cylinder cooling steam bypass inlet isolation valve; 7, outlet isolation valve; 8, low-pressure cylinder cooling water regulating valve; 9, inlet isolation valve; 10, bypass valve; 11, temperature-reducing water spraying device; 12, heat recovery type homogenizer; 13, low-pressure cylinder cooling steam bypass outlet isolation valve; 14, cooling water source; 141, cooling water main path; 142, bypass; 15, flow measuring device.

DETAILED DESCRIPTION

[0026] The present application will be described in detail below with reference to the embodiments. In the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0027] The present application relates to a low-pressure cylinder bypass temperature-reducing and temperature-homogenizing device system, which comprises:

[0028] The low-pressure cylinder cooling bypass water spraying temperature-reducing part comprises the low-pressure cylinder cooling steam bypass inlet isolation valve 6 and the pipeline thereof, the temperature-reducing water spraying device 11 and the temperature-reducing water control and regulating pipeline.

[0029] The system can reduce the temperature of the steam at the bypass inlet of the low-pressure cylinder cooling steam by using desuperheating water, thereby avoiding high exhaust steam temperature of the low-pressure cylinder caused by excessively high inlet steam temperature of the low-pressure cylinder cooling steam, and reducing the use of the cooling desuperheating water flow system of the last-stage and penultimate-stage blades of the low-pressure cylinder, thereby effectively reducing the risk of water erosion of the last-stage and penultimate-stage blades of the low-pressure cylinder.

[0030] The regenerative uniform temperature part includes the regenerative uniform heater 12 and the pipeline in which the low-pressure cylinder cooling steam regulating valve 5 is located. The system can perform filtering and uniform heating, and mixed heating by using regenerative steam, so as to ensure the dryness and adjustable temperature of the bypass cooling steam of the low-pressure cylinder inlet steam, and adjust the exhaust steam temperature of the low-pressure cylinder.

[0031] The low-pressure cylinder cooling steam bypass part includes the pipeline in which the low-pressure cylinder main path cooling steam bypass valve 4 is located. The connection relationship is that the cooling steam introduced from the intermediate-pressure cylinder 2 is connected to the regenerative uniform temperature part after passing through the low-pressure cylinder cooling bypass water spraying and desuperheating part. The pipeline in which the low-pressure cylinder main path cooling steam bypass valve 4 is located in the low-pressure cylinder cooling steam bypass part is directly connected from the intermediate-pressure cylinder 2 to the low-pressure cylinder 3, and the valve 4 is arranged in the pipeline. The system ensures the matching degree of the total flow of the low-pressure cylinder inlet steam, the unit back pressure and the exhaust steam temperature of the low-pressure cylinder.

[0032] The temperature of the cooling steam entering the low-pressure cylinder can be adjusted according to the power generation load, heat supply load, unit back pressure and low-pressure cylinder exhaust steam temperature of the unit, and the adjustment mode adopts control of the desuperheating water flow, the regenerative steam flow entering the regenerative uniform device and the low-pressure cylinder cooling steam main path flow.

[0033] The cooling steam introduced from the intermediate-pressure cylinder 2 is connected to the desuperheating water spraying device after passing through the pipeline of the low-pressure cylinder cooling steam bypass inlet isolation valve 6. The desuperheated cooling steam and the steam introduced from the pipeline in which the low-pressure cylinder cooling steam regulating valve 5 is located are merged into the regenerative uniform heater 12, and the mixed steam enters the low-pressure cylinder 3.

[0034] The mixed steam in the regenerative uniform heater 12 enters the low-pressure cylinder 3 through the flow measuring device 15 and the low-pressure cylinder cooling steam bypass outlet isolation valve 13.

[0035] The desuperheating water control and adjustment pipeline includes a cooling water source 14, a cooling water main pipeline 141, a bypass 142, a bypass valve 10, a low-pressure cylinder cooling water regulating valve 8, an outlet isolation valve 7 and an inlet isolation valve 9. The cooling water source is divided into the cooling water main pipeline 141 and the bypass 142. The bypass valve 10 is arranged on the bypass 142, and the low-pressure cylinder cooling water regulating valve 8 is arranged on the cooling water main pipeline 141. The inlet isolation valve 9 and the outlet isolation valve 7 are respectively arranged at the front end and the rear end of the low-pressure cylinder cooling water regulating valve 8. The cooling water source can use condensate water or other desuperheating water meeting the requirements of pressure, temperature, flow and water quality.

[0036] In order to facilitate monitoring and automatic control of the low-pressure cylinder cooling steam bypass and the low-pressure cylinder admission parameter during operation, pressure and temperature measuring points can be installed at necessary positions to monitor and participate in intermediate point calculation, and a flow orifice plate is installed before the cooling steam enters the low-pressure cylinder to monitor and control the bypass admission flow in real time. The pressure is designed as a two-out-of-three absolute pressure measuring point, and the temperature measuring point adopts a platinum resistance or thermocouple type.

[0037] The temperature of the cooling steam entering the low-pressure cylinder is adjustable, which ensures that the low-pressure cylinder last-stage and penultimate-stage blades are not overheated and the cooling steam dryness entering the low-pressure cylinder is not affected, so that the normal operation of the low-pressure cylinder is not affected.

[0038] The regenerative uniform temperature part includes a regenerative uniform temperature device 12 and a pipeline in which a low-pressure cylinder cooling steam regulating valve 5 is located; the pipeline in which the low-pressure cylinder cooling steam regulating valve 5 is located is connected with the regenerative uniform temperature device 12, and the cooling steam led out by the intermediate-pressure cylinder 2 is mixed with the pipeline in which the low-pressure cylinder cooling steam regulating valve is located after passing through the low-pressure cylinder cooling bypass water injection temperature reduction part and then is mixed into the regenerative uniform temperature device.

[0039] The present application has two specific operation modes and control methods:

[0040] (1) A flow of low-pressure cylinder main route cooling steam directly entering the low-pressure cylinder is separately adjusted and operated

[0041] In the case of cylinder cutting operation, the low-pressure cylinder cooling steam temperature meets the condition that the low-pressure cylinder exhaust temperature is not high (usually not more than 70 DEG C, different manufacturers have different requirements), at this time, the low-pressure cylinder last-stage and penultimate-stage blades do not need to use the water injection for temperature reduction, and the low-pressure cylinder main route cooling steam bypass steam can directly enter the low-pressure cylinder for cooling;

[0042] The operation mode of the system is that in the cylinder cutting operation state, the intermediate-pressure cylinder 2 heat supply exhaust steam directly enters the heat network heater, and the steam in the pipeline in which the low-pressure cylinder main route cooling steam regulating valve is located enters the low-pressure cylinder 3 for cooling. In this condition, the last-stage and penultimate-stage exhaust temperatures of the low-pressure cylinder 3 are not over standard, and water injection for temperature reduction is not needed.

[0043] Under the condition of the above operation mode (1), the low-pressure cylinder bypass temperature reduction and uniform temperature device system is not put into operation.

[0044] (2) A flow of low-pressure cylinder bypass cooling steam is adjusted by the regenerative uniform temperature device 12 and is used with a certain fixed small cooling steam flow of the low-pressure cylinder main route cooling steam bypass valve 4

[0045] The low-pressure cylinder bypass cooling steam flow is adjusted by the regenerative heater 12 and then is used with the low-pressure cylinder main cooling steam bypass valve 4 in a fixed small cooling steam flow operation mode. Specifically, in the case of a cylinder cut-off condition, the low-pressure cylinder cooling steam temperature is too high, which leads to a high low-pressure cylinder exhaust temperature (usually greater than 70℃, which varies according to different manufacturers). At this time, the low-pressure cylinder cooling steam bypass is adjusted by the regenerative heater 12 and then is used with the low-pressure cylinder main cooling steam valve 4 in a fixed small cooling steam flow. At this time, the low-pressure cylinder final stage blade and the penultimate stage blade can not be used, and there is no water erosion risk for the low-pressure cylinder final stage and the penultimate stage blade.

[0046] The operation mode of the system is that the medium-pressure cylinder 2 of the steam turbine directly enters the heat network heater in the cylinder cut-off operation state. The thermal power generating unit enters a low-pressure cylinder cooling small flow condition at a low load, especially when the hot section extraction steam, industrial extraction steam, and heat network extraction steam are used simultaneously. Under the condition of meeting the use of the heating load pressure, the low-pressure cylinder cooling steam inlet temperature is increased, and the exhaust temperature is also increased. The temperature of the flow passage of the low-pressure cylinder is increased as a whole. With the depth of the cylinder cut-off, the low-pressure cylinder exhaust temperature is greater than or equal to 70℃, the volume flow is small, and the low-pressure cylinder enters a blast operation condition. In order to reduce the final stage exhaust temperature, the conventional modification method needs to be modified by spraying water for temperature reduction, and the low-pressure cylinder final stage blade needs to be modified by spraying. The conventional modification of the final stage blade has the risk of water erosion, and the penultimate stage has the risk of serious over-temperature.

[0047] For example, in the low-pressure cylinder cooling bypass system of a 300MW unit, the cooling flow is designed according to the basic cooling flow of 40t / h of the low-pressure cylinder at a small output. The cooling range of the system is preliminarily designed to be cooled from 320℃ to 220℃. In operation, the minimum low-pressure cylinder inlet temperature is not less than 200℃.

[0048] The low-pressure cylinder cooling steam bypass inlet isolation valve 6 is first sprayed by the temperature reduction water spraying device 11 with good atomization effect, and then is filtered and heated by the regenerative heater 12 to reduce the low-pressure cylinder inlet temperature and ensure the steam dryness entering the low-pressure cylinder and the normal operation of the thermal-electric decoupling of the unit in the cylinder cut-off condition.

[0049] In the low-pressure cylinder small output operation of the unit, the reheat steam pressure is between 1-2MPa in the 20%-40% load range of the unit. The change of the pressure ratio of the medium-pressure cylinder inlet and exhaust will obviously change the medium-pressure cylinder exhaust temperature. The pressure ratio changes from 4-10, and the temperature changes more than 100℃. Especially in the ultra-low load operation, in order to maintain a certain heating extraction steam pressure, the pressure ratio of the medium-pressure cylinder inlet and exhaust is between 4-5, and the medium-pressure cylinder exhaust temperature will exceed 300℃, which will also affect the low-pressure cylinder exhaust temperature.

[0050] In the operation mode of the low-pressure cylinder cooling steam 6 passing through the desuperheating device 11 and the temperature equalizing device 12, the low-pressure cylinder cooling steam pipeline 4 valve has a small opening degree, and the low-pressure cylinder cooling steam is cooled in the desuperheating device 11 through the pipeline 6, and the cooled steam enters the temperature equalizer 12 for filtering and temperature equalizing, and is mixed with a certain fixed small cooling steam flow of the low-pressure cylinder main line to enter the low-pressure cylinder;

[0051] The cooling water pipeline system includes a cooling water source 14 and a cooling water main pipeline 141, wherein 8 is a low-pressure cylinder cooling cooling water regulating valve, which can be electric or steam driven; the outlet isolation valve 7 and the inlet isolation valve 9 are manual valves before and after the low-pressure cylinder cooling water regulating valve 8; the bypass valve 10 is a bypass of the cooling water main pipeline 141, which is opened when the main pipeline valve fails to use the pipeline with the bypass valve 10 as a backup;

[0052] The cooled low-pressure cylinder cooling steam is mixed with the low-pressure cylinder cooling steam in the regenerative temperature equalizer 12 to ensure that the temperature of the low-pressure cylinder cooling steam and the temperature of the low-pressure cylinder exhaust steam are within a reasonable range. The low-pressure cylinder final blade area is sprayed with water, effectively eliminating the risk of water erosion.

[0053] The low-pressure cylinder cooling steam bypass outlet isolation valve 13 can be closed in the bypass operation condition, the unit maintenance condition and the summer pure condensation condition. The flow measuring device 15 can measure the steam flow entering the low-pressure cylinder.

[0054] The above is only the preferred embodiment of the present application, and does not limit the present application in any form. Although the present application is disclosed as above, it is not intended to limit the present application. Any skilled person in the art can make some changes or modifications to the above disclosed technical content without departing from the scope of the present application, and any simple modification, equivalent change and modification of the above embodiment within the scope of the present application are within the scope of the present application.

Claims

1. A low pressure cylinder bypass desuperheating and uniform temperature device system, characterized in that, The system comprises: a low-pressure cylinder cooling bypass water injection temperature reduction part, including a pipeline where a low-pressure cylinder cooling steam bypass inlet isolation valve (6) is located, a water injection device (11) for temperature reduction, and a temperature reduction water control and adjustment pipeline; a backheating temperature equalization part, including a backheating temperature equalizer (12) and a pipeline where a low-pressure cylinder cooling steam adjustment valve (5) is located; and a low-pressure cylinder cooling steam bypass part, including a pipeline where a low-pressure cylinder main pipeline cooling steam bypass valve (4) is located; wherein the cooling steam led out from the intermediate-pressure cylinder is connected to the backheating temperature equalization part after passing through the low-pressure cylinder cooling bypass water injection temperature reduction part, and the pipeline where the low-pressure cylinder main pipeline cooling steam bypass valve in the low-pressure cylinder cooling steam bypass part is directly connected from the intermediate-pressure cylinder to the low-pressure cylinder, a valve is arranged in the pipeline, the cooling steam led out from the intermediate-pressure cylinder is connected to the water injection device (11) for temperature reduction after passing through the pipeline where the low-pressure cylinder cooling steam bypass inlet isolation valve (6) is located, the cooling steam after temperature reduction is introduced into the backheating temperature equalizer (12) together with the steam introduced from the pipeline where the low-pressure cylinder cooling steam adjustment valve (5) is located, the mixed steam enters the low-pressure cylinder (3), the mixed steam in the backheating temperature equalizer (12) enters the low-pressure cylinder (3) through a flow measurement device (15) and a low-pressure cylinder cooling steam bypass outlet isolation valve (13), and the temperature reduction water control and adjustment pipeline comprises a cooling water source (14), a cooling water main pipeline (141), a bypass (142), a bypass valve (10), a low-pressure cylinder cooling water adjustment valve (8), an outlet isolation valve (7), and an inlet isolation valve (9), the cooling water source is divided into the cooling water main pipeline and the bypass, the bypass valve is arranged on the bypass, the low-pressure cylinder cooling water adjustment valve (8) is arranged on the cooling water main pipeline, and the inlet isolation valve and the outlet isolation valve are respectively arranged at the front end and the rear end of the low-pressure cylinder cooling water adjustment valve.

2. The low pressure casing bypass desuperheating and uniform temperature device system according to claim 1, characterized in that, The cooling water source needs to meet the requirements of pressure, temperature, flow, and water quality.

3. A control method of a low-pressure cylinder bypass desuperheating and uniform-temperature device system, characterized by, The control method is specifically applied to the low-pressure cylinder bypass temperature reduction and temperature equalization device system as claimed in claim 1 to control: in the cylinder cutting working condition, different power generation loads and heat supply loads of the unit are flexibly selected to select the operation mode of the low-pressure cylinder bypass temperature reduction and temperature equalization device system, and the operation mode comprises: a flow of low-pressure cylinder main pipeline cooling steam directly entering the low-pressure cylinder is separately adjusted; and a flow of low-pressure cylinder bypass cooling steam is adjusted after passing through the backheating temperature reduction and temperature equalization device and is used together with a certain fixed small flow of low-pressure cylinder main pipeline cooling steam.

4. The control method of the low-pressure cylinder bypass de-superheating and uniform-temperature device system according to claim 3, characterized by, The flow of low-pressure cylinder main pipeline cooling steam directly entering the low-pressure cylinder is separately adjusted, specifically: in the cylinder cutting working condition, the low-pressure cylinder cooling steam temperature meets the condition that the low-pressure cylinder exhaust temperature is not high, at this time, the low-pressure cylinder last-stage blade and the penultimate blade do not use the temperature reduction water, at this time, the low-pressure cylinder last-stage blade and the penultimate blade have no water erosion risk, and the low-pressure cylinder main pipeline cooling steam can directly enter the low-pressure cylinder for cooling.

5. The control method of the low-pressure cylinder bypass de-superheating and uniform-temperature device system according to claim 3, characterized by, The operation mode of the low-pressure cylinder bypass cooling steam flow passing through the temperature-reducing and temperature-homogenizing device for heat regulation and being used with a certain fixed small cooling steam flow of the main path of the low-pressure cylinder is as follows: in the case that the low-pressure cylinder cooling steam temperature is relatively high, which leads to the high low-pressure cylinder exhaust steam temperature, at this time, the low-pressure cylinder bypass cooling steam flow passing through the temperature-reducing and temperature-homogenizing device for heat regulation and being used with a certain fixed small cooling steam flow of the main path of the low-pressure cylinder, at this time, the temperature-reducing water for the last-stage blades and the penultimate-stage blades of the low-pressure cylinder can not be used, at this time, the last-stage blades and the penultimate-stage blades of the low-pressure cylinder have no risk of water erosion.

6. The control method of the low-pressure cylinder bypass de-superheating and uniform-temperature device system according to claim 3, characterized by, Each regulating valve can be automatically controlled according to the low-pressure cylinder exhaust steam temperature or the low-pressure cylinder cooling steam inlet temperature, so as to ensure that the low-pressure cylinder cooling steam inlet temperature and the low-pressure cylinder exhaust steam temperature are within a reasonable range.

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